Glass fabric road



C. ELLIS GLASS FABRIC ROAD April 26, 1938.

Filed Jan. 9, 1937 INVENTOR Patented Apr. 26, 1938 GLASS FABRIC ROADCarleton Ellis, Montclair, N. J., asslgnor to Ellis Laboratories, Inc.,a. corporation of New Jer- Application January 9, 1937, Serial No.119,770

Claims.

This invention relates to the construction of asphalt roads andparticularly to those roads on which the asphalt layer or coating isreinforced and bonded by means of a vitreous, siliceous binding agent.

Py incorporating a vitreous siliceous binding or reinforcing agent withasphalt, my invention has for one object the elimination of, or to alarge degree the prevention of, cracks in the asphalt due to the upwardpressure, or heaving, of the road surface. Such distortion is broughtabout in cold weather when the temperature is about freezing (32 F.) orlower, and is due to the freezing or congealing of water or moisture inthe ground. Movement of the asphalt surface,

although small, is nevertheless suflicient to eflect cracking andsubsequent disintegration of. the road. The presence of a binding orreinforcing agent in the asphaltic or bituminous portion may offerconsiderable resistance to such upward D thrusts or movements andtherefore considerably lessen the tendency towards cracks appearing onthe road surface.

.Another object of my invention involves the reduction of disintegrationor breaking of the road surface. Such wearing of the road isparticularly apt to occur at places where cracking, occasioned either byexcessive freezing and thawing due to wide temperature changes or byheavy traiiic, has taken place. The continued running of automobiles,for example, over such openings in the road surfacemay result in thecourse of a short time in many small portions of the asphaltic materialbreaking off and becoming dislodged, eventually giving rise to theformation of holes or other type of depressions. -By incorporating abinding or reinforcing agent to which the bituminous material firmlyadheres or attaches itself this slougliing off or loss of small 0portions of the road surface may be eliminated to a large degree.

It is well known that when atmospheric temperature is high, e. g., inthe summer, asphalt surfaces of roads often become soft, and there is4.5 considerable creeping or flowing of such surfaces due to the passageof vehicles, or other traffic, over them. Retention of this flow orcreeping through adherence of the asphalt to the vitreous, siliceousbonding agent is also within the scope 50 of my invention. Q

It will be recognized thatdiminution in destruction of the road surfaceas a result of incorporation of a vitreous, siliceous bonding agent,according to my invention, will be accompanied also by a decrease inupkeep cost of the road.

This latter item is particularly important as it may amount in someinstances to as much as one thousand dollars per mile of road.

As previously pointed out, the reinforcing agent particularly applicableto my invention is made of vitreous, siliceous material. Preferably suchsiliceous substances, of which glass is an example, is spun into thinfiber-like strands and the latter then woven into the shape of cloth (orfabric) or of narrow tape-like strips. When fashioned in this manner,the siliceous materials possess a desirable degree of flexibilitythereby facilitating their handling. In some instances other syntheticor naturally occurring siliceous and vitreous materials, e. g., rockwool, blast furnace slag wool, asbestos and the like may be employed.

These silica-containing bodies, applicable for my purpose, arecharacterized by their stability towards disintegrating actions such asatmospheric oxidation, and insolubility in many liquids, as for examplewater. These properties of durability render such bonding agentsparticularly applicable for my purpose. Furthermore, when employed inthe forms mentioned above (1. e., as fabric or as ribbon-like strips)they possess a desirable degree of flexibility less likely to be brokenor torn due to small movements in the roadbed either during the layingof the asphalt coating or because of expansion of the latter, forexample in the summer when considerable increases in atmospherictemperatures may take place.

If in the form of cloth or fabric, the siliceous reinforcement may beemployed as such. When tapes or ribbons are employed these may be laid,if desired, in a criss-cross manner upon the roadbed before applying theasphalt. In the latter instance, it is preferable that the strips befastened to one another at the various points of intersections. This maybe accomplished, for example, by means of small wire staples. In thismanner any movement or slipping of the narrow bands of reinforcingmaterial is prevented.

As the bituminous substances I may employ any of those commonly used inroad making such as natural asphalts, petroleum asphalts (which may beobtained either as distillation residues or by air-blowing of heavypetroleum fractions), gilsonite, grahamite, coal-tar pitch, and thelike. These may be employed as such, generally in a molten state inorder to secure even distribution over the surface to which they areapplied, or they may be blended with a liquid medium, often designatedcut-backs, whereby a bituminous or asphaltic composition is obtainedwhich is molten or liquid at much lower temperatures than wouldotherwise be required. Such cut-backs are generally liquids ofsufliciently low volatility that the asphaltic surface of the roadslowly hardens because of the gradual evaporation of the cutback. Anexample of the latter is the gas oil fraction from the distillation ofcrude petroleum. Higheror lower-boiling fractions, e. g., lubricatingoils or kerosene, respectively, may be used in some cases.

My invention may be illustrated by ,the accompanying drawing, which isdiagrammatic in character. The relative thickness of some strata showntherein, in order that I may clearly indicate the construction of theroad, is greater than would be necessary in practice. The same referencefigures are employed to designate the same parts in both figures.

Fig. 1 is a vertical cross-section of a glass fabric road in which thesiliceous reinforcing and bonding agent is a closely woven glass cloth.Fig. 2 is a perspective cross-section of a glass fabric road in whichthe siliceous reinforcing and bonding agent consists of narrow tape-likestrips (woven from glass fibers), the latter being interwoven at rightangles to furnish a netting or screen and being fastened at the variouspoints of intersection.

Referring now to the details of the drawing, i is the earthen or dirtroadbed upon which is placed 2, a layer of gravel or other fairly coarsestone. Upon the latter is spread a coating of asphalt, 3, on which inturn is laid the siliceous bonding and reinforcing agent, I. Aspreviously mentioned, the siliceous agent 4 is shown as a glass cloth inFig. 1 and as interwoven ribbons (made of glass fibers) in Fig. 2. Thebonding and reinforcing agent, 4, is covered with a coating of asphalt,5, to which finely crushed stone, 6, is applied as a finish. Theinterwoven ribbons, or tape-like strips, of the siliceous agent arefastened at the intersections by wire staples, I.

Although the roads described'above are admirably suited for my purpose,itis to be understood that I do notwish to limit my invention to theexact number of layers or strata just mentioned. For example, in someinstances I may find it preferable to place the siliceous bonding agentdirectly on the coarse stone or gravel and then apply a coating ofasphalt. In other cases it may be desirable to have several alternatinlayers of siliceous bonding agent and asphaltic material.

One procedure whereby I may incorporate the vitreous, siliceousreinforcing agent is as follows: Upon the dirt bed of the road is placeda layer of gravel, to serve as a supporting medium for the asphalt. Asufficient quantity of the latter, heated until it fiows readily andeasily, is then spread over the gravel to act as a bonding agent. Whilethis asphaltic material is still liquid and hot, the vitreous, siliceousreinforcing agent is spread upon it. A second layer of molten asphalt isthen applied. In this manner there are obtained two coats of asphaltbonded together and reinforced by the siliceous material. If desired,finely crushed stone may be applied as a finish to the top coat.

As an alternative procedure, the vitreous reinforcement may be spreaddirectly upon the stone base, in which case only one layer of moltenasphalt need be applied. In other instances gravel or crushed rock maybe incorporated with the molten asphalt and the bonding agent thenincorporated between successive coatings of this mixture. On the otherhand it may be desirable to use asphalt emulsions. In such cases, stoneand emulsion can be mixed and the mixture (one or more layers) spreadover the bonding agent.

The following examples will serve to illustrate my invention.

Example 1.Natural asphalt was fluxed with a heavy mineral oil until themixture flowed readily at about 200 C. A base was made using a portionof this fluid asphalt and small rock and, while the asphalt was stillwarm, glass cloth was laid on it. Then on top of the glass was poured alayer of hot fluxed asphalt and the latter covered with small crushedrock. Three more successive thin layers, each consisting of road tar andcrushed rock, were laid upon the top asphalt coat.

Example 2.--Strips of fiber glass tape wide by 0.007" thick) wereinterwoven (at angles) to give a glass screen, the square open portionsof which were about 3" x 3". At each intersection the strands were tiedtogether by means of a small wire staple.

An asphalt road containing this glass screen as a bonding agent was madeby laying the latter on a bed of asphalt to /1," deep) while still softand warm. After the asphalt, with the bonding agentadhering to it, hadpartially cooled another layer (about /2" deep) of molten asphalt waspoured over the glass screen. Crushed stone, to the depth of about inch,was then spread on the top coat of asphalt.

Example 3.-A screen of glass tape (1" wide by 0.02" thick) was preparedas described in Example 2. In this instance, however, the openings inthe screen were about 2 inches square. A glass bonded road, using thisscreen, was made as described in Example 2.

Example 4.--Another screen of glass tape /1" wide by 0.02 thick) wasprepared. as described in Example 2. The openings in the screen thistime were only about 1" square. A glass bonded road, using this screen,was made as described in Example 2.

From the foregoing it will be seen that my invention comprisesincorporation of a vitreous, siliceous bonding and reinforcing agentwith the asphaltic or bituminous layer of coating during construction ofan asphaltic road. Such an agent may be employed in the form of glasscloth or as narrow strips of tape or ribbon. In the latter instance itis preferable that the narrow strips, before incorporation with theasphaltic or bituminous material, be interwoven at right angles to aglass screen or netting. In the latter instance the strips, if desired,may be fastened together at the various points of intersection.

My invention also involves reduction in the formation of cracks in theasphaltic portion of the road due to the exertion of upward pressure, orheaving, brought by freezing oi' water in ground, on which the road islaid, or which may have seeped into the asphaltic layer or the crushedrock which serves as the base for the road. Another phase of myinvention comprises lessening of disintegration of the asphaltic roadsurface by incorporating a vitreous, siliceous bonding agent to whichthe asphaltic or bituminous material firmly adheres' and thereby mayprevent the sloughing off or breaking away of lumps or small portions ofthe roadway.

What I claim is:

1. An asphalt road containing as the flexible, bonding agent a vitreous,siliceous composition ill? - conslstlns fibers present in the iorm orfabric.

7 2. Anasphalt road in which 'a flexible, vitreous,

siliceous bonding agent is presentas cloth woven from glass fibers andis covered with an adhering layer of asphaltic material.

3. An asphalt road in which the flexible, vitreous, siliceous bondingbons woven from glass turmbeln: interwoven to covered with an adherinteriai.

agent is present as-ribfibers, said ribbons in form a glass screen andg' layer of asphaltic. ma-

I 3 4. Anasphaltic road in which a flexible, vitreous, siliceous bondingagent is present as cloth woven from glass fibers and placd between twoadhering layers or asphaltic material.

5. An asphaltic road in which a flexible, vit- 5 reous, siliceousbonding agent is present as ribbons woven from glass fibers, saidribbons in turn being interwoven to form a glass screen and placedbetween two adhering layers of asphaltic material. 10

Cameron ELLIS,

